1. Field of the Invention
The present invention relates to a fixing apparatus and an image forming apparatus including a heat fixing member and a pressure applying member pressure contacting the fixing member.
In particular, the present invention relates to a fixing apparatus and image forming apparatus capable of fixing a toner image to a recording member while directing and conveying the recording member to and through a nip formed between the fixing member and pressure applying member in such a manner that the toner image contacts the fixing member.
2. Discussion of the Background
It has been well known that a fixing apparatus of the above-described type is adopted in an image forming apparatus, such as a copier, a printer, a facsimile, a combined machine having at least one of them, and etc. In such a type of the fixing apparatus, since the toner fuses when passing the nip formed between the fixing and pressure applying members, the toner likely functions as an adhesive agent and the recording member ejected from the nip is not separated and wraps around the surface of the fixing member. In particular, in an image forming apparatus forming a full-color image, since different color toner images are superimposed on a recording member and fixed by a fixing apparatus, toner necessarily fuses in the nip, and thus the adhesive force of the toner increases. As a result, the recording member more readily wraps around the fixing member.
In the past, a separation member including a plurality of separation claws has been configured to contact a surface of a fixing member and separate a recording member ejected from a nip from the surface of the fixing member in order for the recording member not to wrap around the surface of the fixing member. However, since the separation claw contacts the surface of the fixing member via its tip, the surface likely is cut (e.g, damaged). As a result, a mark appears on a toner image after passing through the nip in accordance with the cut, and resulting in inferior toner image quality as a result of fixing.
To avoid such disadvantage, a fixing apparatus is proposed to arrange a separation claw separating from a surface of the fixing member. However, a recording member ejected from the nip likely enters into a gap formed between the fixing member and separation claw while sticking the surface of the fixing member. As a result, the separation function of the recording member is weakened and wrapping likelihood of the recording member around the fixing member increases.
In addition, there exists a case when a fixed toner image is formed on a backside surface of the recording member carrying a toner image on the other side to be fixed. In such situation, since the toner image on the backside surface is fused by heat while passing through the nip, the recording member likely wraps around the surface of the pressure applying member. To avoid such problem, a separation claw preferably contacts the surface of the pressure applying member. However, a similar problem arises as described in the above.